The invention relates to a process for manufacturing an integrated shell element comprising at least one longitudinal or transversal stiffener element, in particular an integrated shell element of an aircraft fuselage or a spacecraft fuselage and a shell element field and the further structures which can be manufactured made from such elements, in particular an aircraft or spacecraft fuselage.
Large scale structures, such as the fuselage of an aircraft or the wing of an aircraft, the body of a carrier rocket, a booster, a spaceship, the module of a space station, a satellite, or similar structures may comprise composite shell elements forming the outer shell (skin) of the large scale structure. Such composite shell elements may be formed from fiber-reinforced composite materials, such as carbon fiber reinforced plastic materials.
Furthermore, the fuselage of an aircraft or spacecraft typically comprises stiffeners running in the longitudinal direction of the fuselage (typically called stingers) and stiffeners running transversely to the stringers in the circumferential direction of the fuselage (typically called ribs or frames). These elements impart to the fuselage the required structural strength and support the outer skin of the fuselage.
The longitudinal stiffeners (stringers) accommodate the longitudinal loads, the transversal or circumferential stiffeners (frames) accommodate the transversal circumferential loads and moments, while the skin primarily accommodates the internal pressure and also longitudinal and shear loads.
System installations and cabin components which have to be installed during the final assembly of the aircraft or spacecraft in large numbers in the fuselage are normally fastened, according to the present state of the art, by means of individual brackets mounted to the frames running in the circumferential direction of the fuselage or to the stringers running in the longitudinal direction of the fuselage.
In an aircraft or spacecraft fuselage based on metal skin elements, the stringers and frames are usually assembled to the skin by rivets or welded seams. In structures based on composite materials, rivets or adhesives are used as means of assembling the frames and stringers to the skin elements.
In a process for manufacturing an aircraft or spacecraft fuselage, stringers and clips/angles are usually first riveted or welded to shell elements (also termed skin field elements herein). Then, the frames are positioned on those shell elements and riveted using the clips. The so supported shell elements are then assembled along the longitudinal direction by riveting the shell elements together in areas of longitudinal overlap. The assembled shell elements that form a skin field are then joined along the vertical direction into straight cylinders that are also referred to as barrels. In a further step, the straight cylinders are joined into an aircraft or spacecraft fuselage by means of a similar process as described above, i.e., by welding or riveting. The types of longitudinal joints (welding, riveting, adhesive bonding) as well as the couplings used have an influence on the overall weight of the aircraft or spacecraft fuselage and the costs and design of the process steps used to achieve the assemblies as described above. After the assembly of the fuselage components, brackets are installed to prepare for systems installations.